Light source control system



.May30,1933. ,w,. 'E G 1,911,371

LIGHT SOURCE CONTROL SYSTEM Original Filed June 7, 1926' INYENfQR J0sap/7 MLeyy, fleceas'ed,

ATTORNEY Patented May 30, 1933 UNITED STATES ATENT OFFICE i .Tosmn w.mace, nncnssnn, Lara or winnnsnuna, rnmzsnvanra, BY E's-rims. L. mass,anmnrsraurnrx, or woacns'rna, mssacnusn'r'rs, ABSIGNOB 'ro wiser;monousn announce ugmurac'runme oouram, a oonrona'rrox or rmmvamaOriginal application am June 7, me,

This invention relates to oscillographs and particularly to means forcontrolling the light sources thereof.

- One object of the invention is to provide means for controlling thelight source of an oscillograph or similar device that shall permit ofinstantaneous illumination of the instrument.

-Another object of the invention is to provide means for maintaining thefilaments of light sources for oscillographs at a desired temperatureafter being heated instantane-' ously.

A further object of the invention is to provide means for suddenlyapplying an ab:

normal voltage to an electro-responsive de vice and for immediatelythereafter maintaining a reduced voltage across said device.

7 intensity to permit the instrument to func A still further object ofthe invention is to provide control means for an oscillograph that shallcondition the same for instant response durin long periods of time torecord conditions 11 a commercial transmission line when a short circuitorlike phenomenon occurs.

In the prior art, the light sources of electrio indicating devices, suchas oscillographs, are not supplied with any means for accel crating theheating thereof, and, therefore, an appreciable length of time isrequired before enough energy is supplied to the light source to causeit to emit light of sufiicient tion. v

The time consumed in bringing a light source, such as the filament of anincandescent lamp, to the required degree of incandesoence isso greatthat it is necessary to await the energization of the light source andmake photographs by employing it shutter. 'This complicates theapparatus and Lrcn'r sounor: con'rnor. srs'rau lamp is heated to a highelements;

temperature in a very brief eriod of time by the dischargethrough it o aquantity of electrical energy stored in an inductance coil,

and the filament is subsequently maintained at a desired temperature bymeans of another energy supply, The time consumed to provide theillumination necessary for the operation of the instrument is so briefas to be almost negligible, and no shutter need be utilized.Furthermore, the filamenticomes to incandesoence so rapidly that thefirst part I of a transient may be recorded...

This application is a division of copending application, Serial No.114,187, filed-June 7 V Other features and advantages of the inventionwill appear from the following de-. scriptlon, taken in connection withthe ac companying drawing the; single'figure of which illustratesdiagrammaticall an embodiment of the invention in whic Referring to thedrawing, the apparatus comprises, in general, an incandescent lamp 1, atransformer 2, a storage battery 3,- a rectifier ,4 shunted byresistance 5 and a control relay :6. The incandescent lamp 1 and thecontrol role, 6 are of usual types The control relay 6 1s a quick-actingrelay which is normally closed and so connected to a transmission line 7that'it will be opened when a-short circuit occurs on the line.

a trans-' former supplies the stored electrical energy.

Serial No. 114,1 87 pivided and this application ill e11 Tune 8, I

1829. serial No. 867,977. 1

The transformer 2, which ma be of the conventional type, isso designasto step down the alternating current supplied -.to the input thereofto a proper value for lighting the incandescent lamp 1, durin the periodthat photographs are being ma e, by the oscillograph. 'The transformercomprises an iron core 8, a prima coil 9 and a secondary coil 10, theprimary coil having many more turns than the secondary coil.

. The rectifier 4 is a one-way rectifier of conventional design adaptedto rectify alternating current flowing therethrough and to supply therectified current to the storage battery 3.

When the control relay 6 is closed,;thrce circuits are provided by theabove-described a pulsatingrcurrentcircuit 11, a

continuous-current circuit 12 and a circuit 13 which carries currentonly'when the instrument is in operation.

The pulsating-current circuit 11 extends from terminals 14 which areconnected to a source of alternating current (not shown) through theupper portion of the resistor 5, through the rectifier 4, the contactmembers of the control relay 6, the battery 3 and back to the otherterminal 14. A relatively large quantity of current flows in thepulsatingcurrent circuit 11 to cause a large drop of potential in theupper portion of the resistor 5, the rectifier 4 being connected acrossa suiiiciently long portion of the resistor 5 to provide an easier pathfor the pulsating current, with the result that virtually all of thecurrent flows through the rectifier 4 and is rectified to pass throughthe battery 3 and maintain it in charged condition.

The continuous-current circuit 12/ extends from one terminal of thebattery 3 through the primary coil 9 of the transformer and across thecontact members of the control relay 6 to the other terminal of thebattery 3. The continuous current, maintains a strong electro-magneticfield in the core of the transformer 2.

The circuit 13 comprises the secondary winding 10 of the transformer andthe light source 1.

The control rela 6 is so connected to the transmission line f, by meansof a transformer 15, that, when current of abnormal value appears on theline, the contact points of the relay 6 will be opened.

The disturbances which occur on the transmission line 7 are recorded ona photographelement 18.

When the control relay 6 is actuated in response to a disturbance on thetransmission line, the relay contacts are opened, and the circuit 12,which carries the current maintaining the electro-magnetic field in thecore of the transformer 2, is broken, and the stored electric energy inthe core discharges instantaneously through the secondary coil 10,thereby providing suflicient current to heat the filament of the lamp 1to a high degree of brilliancy in a very short time.

The opening of the contact members of the control relay 6 also breaksthe pulsatingcurrent circuit, and the alternating current which issupplied to the terminals 14 takes a new course which includes theentire length of the resistor 5, the primary coil 9 of the transformerand the conductor 19.

Oscillographs without a shutter or with the shutter open and suppliedwith a continuously rotating photographic film may be so electricallyconnected to a commercial transmission line as to automatically recordthe current pulsations when any short circuit sufficient to operate thecontrol relay occurs. By this means, records may be obtained of theactual phenomena of a commercial circuit without entailing the risk andexpense incidental to an experimental short circuit which is required atthe present time because the oscillograph of the prior art requires anappreciable t me for the light source to heat up to full brilliancy.

Various modifications may be made in the invention without departingfrom the spirit and scope thereof, and it is desired, therefore, thatonly such limitations shall be placed thereon as are shown by the priorart and set forth in the appended claims.

What is claimed:

1. Electrical apparatus com rising an electro-responsive device, a transormer having a primary and a secondary, said electroresponsive devicebeing connected to said secondary, a storage attery, means for chargingsaid battery through a charging circuit, means for passing a continuousflow of direct current from said battery through said primary while saidbattery is being charged, and means for suddenly interrupting the flowof direct current through said primary and for simultaneously breakingsaid charging circuit.-

2. In combination, an electro-responsive device, a transformer having aprimary and a secondary, said electro-responsive device being connectedto said secondary, a storage battery, means including a charging circuitfor normally passing a charging current through said battery, meansincluding a portion of said charging circuit for connecting said batteryto said primary whereby a continuous flow of direct current is normallymaintained therethrough, and means for interrupting said portion of thecharging circuit whereby the flow of direct current through said primaryis interrupted.

3. Electrical apparatus comprising an electro-responsive device, atransformer having a primary and a secondary, said electro-responsivedevice being connected to said secondary, a storage battery, meansincluding a rectifier for charging said battery, an impedance unitconnected in shunt to said rectifier, means for passing a flow of directcurrent from said battery through said primary, means for interruptingsaid flow, and means including said impedance unitfor maintaining a flowof alternating current through said primary immediately after theinterruption of said flow of direct cur rent.-

4. Electrical apparatus comprising a transformer having a primary and asecondary, an electro-responsive device connected to said secondary,means for passing a flow of direct current through said primary, meansfor interrupting said flow of direct current, and means for passing acontinuous flow of alternating current through said primary in responseto the interruption of said flow of direct current.

5. Electrical apparatus com rising a transformer having a primary an asecondary, an incandescent lamp connected to said secondary, means forpassing a flow of direct current through said primary, means forinterrupting said flow of direct current in response to an electricaldisturbance, and means for passing a continuous flow of alternating.vcurrent through said primary in response to said interruption.

6. Electrical apparatus com rising a transformer having a primary an asecondary, a light source connected to said secondary, means for passinga flow of direct current through said primary, and means for inducing acontinuous flow of alternating current in said secondary in response tothe interruption of said flow of direct current.

In testimony whereof, I have hereunto subscribed my name this 27th dayof May 1929.

ESTHER L. LEGG, Administratrim 0f the Estate of Joseph W.

Legg, Deceased.

